'The Ringer' (CW)

Sarah Michelle Gellar stars as a marked woman on the run who takes on her twin sister's identity, only to realize her sibling's life isn't danger-free either. After witnessing a professional hit, Gellar's Bridget reunites with her estranged twin sister and slips into her sibling's shoes/marriage/penthouse after she mysteriously disappears. Gellar plays both roles, Bridget and Siobhan, whose wealthy, idyllic life looked a lot better from the outside. The thriller, originally developed for CBS, also stars Nestor Carbonell of "Lost," Tara Summers, Kristoffer Polaha and Ioan Gruffudd. It will air with "90210" on Tuesdays. RELATED: The CW's fall lineup includes the return of Sarah Michelle GellarSarah Michelle Gellar clones herself for 'Ringer'Video: Watch a sneak preview of 'The Ringer' Photo: Sarah Michelle Gellar in "The Ringer." -- T.L. Stanley

Sarah Michelle Gellar stars as a marked woman on the run who takes on her twin sister's identity, only to realize her sibling's life isn't danger-free either. After witnessing a professional hit, Gellar's Bridget reunites with her estranged twin sister and slips into her sibling's shoes/marriage/penthouse after she mysteriously disappears. Gellar plays both roles, Bridget and Siobhan, whose wealthy, idyllic life looked a lot better from the outside. The thriller, originally developed for CBS, also stars Nestor Carbonell of "Lost," Tara Summers, Kristoffer Polaha and Ioan Gruffudd. It will air with "90210" on Tuesdays. RELATED: The CW's fall lineup includes the return of Sarah Michelle GellarSarah Michelle Gellar clones herself for 'Ringer'Video: Watch a sneak preview of 'The Ringer' Photo: Sarah Michelle Gellar in "The Ringer." -- T.L. Stanley

Sarah Michelle Gellar stars as a marked woman on the run who takes on her twin sister's identity, only to realize her sibling's life isn't danger-free either. After witnessing a professional hit, Gellar's Bridget reunites with her estranged twin sister and slips into her sibling's shoes/marriage/penthouse after she mysteriously disappears. Gellar plays both roles, Bridget and Siobhan, whose wealthy, idyllic life looked a lot better from the outside. The thriller, originally developed for CBS, also stars Nestor Carbonell of "Lost," Tara Summers, Kristoffer Polaha and Ioan Gruffudd. It will air with "90210" on Tuesdays. RELATED: The CW's fall lineup includes the return of Sarah Michelle GellarSarah Michelle Gellar clones herself for 'Ringer'Video: Watch a sneak preview of 'The Ringer' Photo: Sarah Michelle Gellar in "The Ringer." -- T.L. Stanley